Enzymatic Synthesis of N-Acetylglucosaminyl-cyclodextrin by the Reverse Reaction of N-Acetylhexosaminidase from Jack Bean

Abstract

  Novel heterobranched cyclodextrins (CDs), N-acetylglucosaminyl-cyclodextrins (GlcNAc-CD), were synthesized from a mixture of GlcNAc and α, β, or γCD by the reverse reaction of N-acetylhexosaminidase from jack bean. Optimum pH and temperature for the production of GlcNAc-αCD by N-acetylhexosaminidase were pH 4.9 and 50-70°C, respectively. The maximum yield of GlcNAc-αCD was 17.5% (mol/mol) at the concentration of 1 M GlcNAc and 0.25 M αCD. The reverse reaction product, GlcNAc-αCD, was separated into two peaks by HPLC analysis on the ODS column. Their structures were identified as 6-O-β-D-N-acetylglucosaminyl-αCD and 2-O-β-D-N-acetylglucosaminyl-αCD by FAB-MS and NMR spectroscopies. N-Acetylhexosaminidase from jack bean also synthesized N-acetylgalactosaminyl-αCD from N-acetylgalactosamine and αCD.